{"id":"F2006B11004","name":"AD/JT9D/11 - No. 4 Bearing Compartment","slug":"ad-jt9d-11-no-4-bearing-compartment","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":56600,"registerId":"commonwealth-F2006B11004-current","compilationNumber":null,"startDate":"2026-04-02","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/JT9D/11 - No. 4 Bearing Compartment","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 22.10.0\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\nCOMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 106 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n \n\n![](image.001.png)  Pratt and Whitney Turbine Engines - JT9D Series\n\n \n\nAD/JT9D/11 No. 4 Bearing Compartment 10/78\n\nApplicability: All JT9D engines except those fitted with an annular strainer element in accordance with PWA SB No. 4860.\n\n \n\nDocument: 1. FAA AD 78-16-05: Amendment 39-3274; or\n\n \n\n2. Pratt & Whitney Aircraft Alert SB No. 4826; or 3. AD/PW-T/48.\n\nCompliance: As detailed in Requirement Document No. 1.\n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n\n \n","sortOrder":0}],"analysis":{"kimi_summary":{"content_quality":"ok","complexity_score":2,"scope_assessment":{"changed":false,"description":"This is a narrow, technical maintenance directive focused on a specific engine component. It has not expanded beyond its original purpose of addressing the No. 4 Bearing Compartment issue in JT9D engines."},"complexity_factors":["Very short document (approximately 200 words)","Only 1 substantive requirement (compliance with referenced FAA document)","Single exemption clause (annular strainer element per PWA SB 4860)","No defined terms section — relies entirely on external references","No conditional logic or nested exceptions within the text itself","Cross-references to 3 external documents but does not reproduce their content"],"plain_english_summary":"This is an **Airworthiness Directive (AD)** — a mandatory safety order issued by Australia's Civil Aviation Safety Authority (CASA) under the Civil Aviation Regulations 1998.\n\n**What it does:**\nThis directive (AD/JT9D/11) requires specific maintenance or inspection actions on **Pratt & Whitney JT9D series turbine engines**, specifically concerning the **No. 4 Bearing Compartment**.\n\n**Who it affects:**\n- **Operators and maintainers** of aircraft powered by JT9D engines (commonly used on Boeing 747, 767, and Airbus A300 aircraft)\n- **Exemption:** Engines that have already been modified with an \"annular strainer element\" per Pratt & Whitney Service Bulletin 4860 are exempt from this directive\n\n**Why it matters:**\nAirworthiness Directives are legally enforceable safety mandates. They typically address discovered defects, wear patterns, or failure risks that could affect flight safety. Non-compliance can ground aircraft and expose operators to penalties.\n\n**How to comply:**\nOperators must follow the detailed instructions in **FAA AD 78-16-05** (the US Federal Aviation Administration's equivalent directive), which CASA has adopted for Australian operations."},"flash_summary":{"complexity_score":4,"scope_assessment":{"changed":false,"description":"The supplied text does not indicate any change from a prior or original scope. It sets applicability to all JT9D engines except those fitted with an annular strainer element per PWA SB No. 4860 and mandates compliance as detailed in Requirement Document No. 1, with acceptable compliance documents listed (\"Applicability\", \"Document\", and \"Compliance\" lines). There is no statement in the supplied text that expands or narrows that applicability beyond what is quoted."},"complexity_factors":["Relies on multiple external documents for substantive requirements (FAA AD 78-16-05; P&W SB No. 4826; AD/PW-T/48) (\"Document\" lines).","Exemption based on specific equipment fitment (annular strainer per PWA SB No. 4860) requires verification of engine configuration (\"Applicability\" line).","The AD does not contain technical procedures itself; all technical detail is in a separate Requirement Document No. 1 (\"Compliance\" line).","Cross‑jurisdictional references (Australian AD referencing an FAA AD and manufacturer SBs) introduce coordination and interpretation considerations (header and \"Document\" lines).","Short form of the AD leaves timing, scope of mandatory actions, and enforcement details to the referenced Requirement Document, increasing the need to consult multiple documents (\"Compliance\" line)."],"plain_english_summary":"This Australian airworthiness directive (AD) requires operators of Pratt & Whitney JT9D engines to carry out mandatory corrective/inspection action for the No.4 bearing compartment by following a nominated Requirement Document (FAA AD 78‑16‑05, P&W Alert SBs or AD/PW‑T/48). Engines fitted with the annular strainer element per P&W SB No.4860 are excluded. CASA issues the AD; compliance and any costs fall to engine owners/operators, who must consult the referenced documents for technical detail."}},"importantCases":[],"_links":{"self":"/api/acts/ad-jt9d-11-no-4-bearing-compartment","history":"/api/acts/ad-jt9d-11-no-4-bearing-compartment/history","analysis":"/api/acts/ad-jt9d-11-no-4-bearing-compartment/analysis","conflicts":"/api/acts/ad-jt9d-11-no-4-bearing-compartment/conflicts","importantCases":"/api/acts/ad-jt9d-11-no-4-bearing-compartment/important-cases","documents":"/api/acts/ad-jt9d-11-no-4-bearing-compartment/documents"}}